PubMed Health⌕ Search

Biomedical subjects

A Kanamori

Publications and source records attributed to A Kanamori.

At least 19 recordsLinked to original sources
PubMed2005

Macular thickness reduction in eyes with unilateral optic atrophy detected with optical coherence tomography.

AIMS: To assess the changes in macular and peripapillary retinal nerve fibre layer (RNFL) thickness in eyes with unilateral optic atrophy and to evaluate the relationship between retinal thickness and visual function. METHODS: Enrolled were 22 patients with unilateral optic atrophy. Macular thickness at the divided nine areas and peripapillary RNFL thickness in quadrantic sections were measured by optical coherence tomography. Thickness values in the affected eyes were compared with those in the contralateral unaffected eyes. The correlation of foveal thickness with best-corrected visual acuity (BCVA) was evaluated. The correlation between retinal thickness and the remaining visual field area circumscribed with I-4-e isopter in superior and inferior hemifield was assessed. RESULTS: Macular thinning was observed in all areas (P < 0.001 in each area) other than the fovea (P = 0.068). Peripapillary RNFL thickness decreased in all quadrantic sections (P < 0.001 in each section). The affected to unaffected eye ratio of retinal thickness was more than 0.6 in each area. BCVA did not correlate with foveal thickness (correlation coefficient = 0.094, P = 0.668). Although not statistically significant (P = 0.281, superior hemifield; P = 0.053, inferior hemifield), there was a tendency that eyes with severe visual field loss show more marked retinal thinning. CONCLUSIONS: Macular thinning with the preserved foveal thickness is a hallmark of eyes with optic atrophy. Together with no correlation between foveal thickness and BCVA, this finding would help in differential diagnosis of macular and optic nerve diseases.

Adult↗
PubMed2004

Germ cell-less expression in medaka (Oryzias latipes).

The gene germ cell-less (gcl) plays an important role in the early differentiation of germ cells in Drosophila. We isolated the gcl homolog of the model teleost medaka (Oryzias latipes) using degenerated primers and an ovary cDNA bank. The predicted amino acid sequence of medaka gcl showed 92, 68 and 31% overall identity to mouse, human and Drosophila gcl respectively. RT-PCR revealed stronger expression in the ovary and weaker expression in testis, brain, heart, liver and muscle tissue. Expression in early embryos indicates the presence of maternal mRNA. By in situ hybridisation (ISH), gcl could not be detected in embryos. In contrast to vasa, ISH revealed expression of gcl in the ovary but not in the testis. Mol. Reprod. Dev. 67: 15-18, 2004.

Amino Acid Sequence↗
PubMed2002

Gastrin and Helicobacter pylori in low-grade MALT lymphoma patients.

BACKGROUND: This study of patients with Helicobacter pylori infection and low-grade MALT lymphoma aimed to investigate: 1) the effect of H. pylori eradication therapy on the serum gastrin level, 2) whether changes of the serum gastrin level after therapy could predict the prognosis of patients with this tumour, and 3) the relationship between the gastric H. pylori load, the serum gastrin level and the status of MALT lymphoma. METHODS: Thirteen patients with documented low-grade MALT lymphoma and H. pylori infection were enrolled and received H. pylori eradication therapy as the sole initial treatment. The presence of H. pylori, the serum gastrin level, the endoscopic findings, the pathologic features of the biopsies and resected specimens, and the endoscopic ultrasonography findings were evaluated before and after therapy. Follow-up was carried out every 3-6 months. RESULTS: H. pylori eradication was eventually achieved in all 13 patients. The pretreatment fasting serum gastrin level decreased from 177.1 +/- 107.4 pg/ml to 129.2 +/- 78.1, 96.4 +/- 66.6 and 80.1 +/- 42.7 pg/ml after 0-3, 3-6 and 6-9 months, respectively (all P < 0.05). Successful eradication of H. pylori was followed by a decrease of the fasting serum gastrin level and complete regression of initial low-grade MALT lymphoma was observed in all patients. However, two patients subsequently developed recurrent high-grade MALT lymphoma or high-grade lymphoma. In one of them, the serum gastrin level rose again above the pretreatment value. In the other, however, the fasting gastrin level fell throughout the study period. The median fasting serum gastrin level before H. pylori eradication therapy was higher in the patients with tumours of the gastric body (203.4 +/- 108.9 pg/ml) than in those with tumours of the antrum and angulus (89.3 +/- 28.0 pg/ml) (P = 0.06). CONCLUSIONS: Hypergastrinaemia may be associated with an increased risk of gastric MALT lymphoma.

Adult↗
PubMed2001

[Three ocular sarcoidosis patients examined by indocyanine green angiography].

PURPOSE: To assess the findings of indocyanine green angiography(IA) in patients with ocular sarcoidosis. SUBJECTS AND METHODS: Three active ocular sarcoidosis patients with various retinochoroidal findings diagnosed by biopsy or systemic examination. Two patients were diagnosed pathologically and one patient was diagnosed clinically. IA & fluorescein angiography(FA) were performed before and after treatment with systemic steroid administration. RESULTS: IA revealed hyperfluorescence surrounding the presumed granulomatous lesions. This hyperfluorescence disappeared immediately after the treatment. FA showed hyperfluorescence continuing even after therapy. CONCLUSIONS: It is purposed that the ring-form hyperfluorescence in IA is due to accelerated vascular permeability in the active sarcoid granuloma. IA, which vividly reflects activity of sarcoid lesions, is an important tool for clinical evaluation of ocular sarcoidosis.

Aged↗
PubMed2001

[MR imaging of posterior cruciate ligament injuries].

Posterior cruciate ligament(PCL) injuries are less frequent than anterior cruciate ligament(ACL) injuries, but are presumably more common than once thought. Thirty-nine patients with PCL injuries identified on MR images were studied. The criteria for PCL injury were complete tear, partial tear, and avulsion fracture. The approximate site of a partial tear was categorized as proximal, midsubstance, distal, or combination. Fourteen patients(35.9%) had complete tears of the PCL, 21 patients(53.8%) had partial tears, and four patients(10.3%) had avulsion fractures. A total of 12 patients (30.7%) had isolated PCL injuries, while the remaining 27 patients demonstrated evidence of other coexistent knee injuries, such as meniscal tears and ligamentous injuries. Of coexistent knee injuries, meniscal tears(18 patients, 46.2%) were most often seen.

Adolescent↗
PubMed2000

P- and E-selectins recognize sialyl 6-sulfo Lewis X, the recently identified L-selectin ligand.

Recently we identified sialyl 6-sulfo Le(x) as a major L-selectin ligand on high endothelial venules of human peripheral lymph nodes. In this study we investigated the ligand activity of sialyl 6-sulfo Le(x) to E- and P-selectins and compared it with the binding activity of conventional sialyl Le(x), by using cultured human lymphoid cells expressing both carbohydrate determinants. The results of the recombinant selectin binding studies and the nonstatic monolayer cell adhesion assays indicated that both sialyl 6-sulfo Le(x) and conventional sialyl Le(x) served as ligand for E- and P-selectins, while L-selectin was quite specific to sialyl 6-sulfo Le(x). Anti-PSGL-1 antibodies as well as O-sialoglycoprotein endopeptidase treatment almost completely abrogated the binding of P-selectin but barely affected the binding of E-selectin, indicating that these carbohydrate determinants carried by O-glycans of PSGL-1 selectively serves as a ligand for P-selectin, while the ligand for E-selectin is not restricted to PSGL-1 nor to O-sialoglycoprotein endopeptidase-sensitive glycans. The binding of L-selectin was markedly reduced by O-sialoglycoprotein endopeptidase treatment but only minimally affected by anti-PSGL-1 antibodies, indicating that O-glycans carrying sialyl 6-sulfo Le(x) were the major L-selectin ligands, while PSGL-1 was only a minor core protein for L-selectin in these cells. These results indicated that each member of the selectin family has a distinct ligand binding specificity.

Animals↗
PubMed2000

Genomic structure and promoter analysis of putative mouse acetyl-CoA transporter gene.

The acetyl-CoA transporter gene (Acatn) encodes a hydrophobic, multitransmembrane protein that is involved in the process of O-acetylation of sialic acid residues on gangliosides. O-Acetylated gangliosides have been found to play important roles in tissue development and organization during early embryonic stages. We have cloned the gene for mouse acetyl-CoA transporter. The gene spans approximately 20 kb and is composed of seven exons and six introns. A single transcription initiation site, 371 bp upstream of the ATG start codon, was identified. The promoter region was found to lack a TATA box. However, several potential transcription factor binding motifs such as AP1, AP2, C/EBPalpha, C/EBPbeta, HSF, GATA2 and MZF1 were identified in the promoter region.

Animals↗
PubMed2000

Expression of sialyl 6-sulfo Lewis X is inversely correlated with conventional sialyl Lewis X expression in human colorectal cancer.

Sialyl 6-sulfo Lewis X determinant has been described recently as a major ligand for L-selectin on high endothelial venules of human peripheral lymph nodes. From our investigation of its distribution in human colorectal cancer tissues and cultured colon cancer cells, the sialyl 6-sulfo Lewis X determinant was preferentially expressed in the nonmalignant colonic epithelia rather than cancer cells (P < 0.001; n = 23). This was in contrast to the distribution of conventional sialyl Lewis X, which was preferentially expressed in cancer tissues rather than nonmalignant epithelia (P = 0.007; n = 23), indicating that 6-sulfation predominantly occurs in nonmalignant tissues and is suppressed upon malignant transformation. In confirmation of this, a nonsialylated determinant 6-sulfo Lewis X was also found to be preferentially localized in the nonmalignant epithelia. Significant expression of sialyl 6-sulfo Lewis X was observed in only 2 lines, whereas 8 were positive for conventional sialyl Lewis X, among 13 cultured colon cancer cell lines. Transfection of cells with fucosyltransferase (Fuc-T) VI induced expression of sialyl 6-sulfo Lewis X, whereas transfection of Fuc-T III did not, suggesting that the determinant was synthesized mainly by Fuc-T VI in colonic epithelia. Members of the sialic acid cyclase pathway, the de-N-acetyl sialyl 6-sulfo Lewis X and cyclic sialyl 6-sulfo Lewis X determinants, were also preferentially expressed in the nonmalignant epithelia rather than colonic cancer cells (P < 0.001; n = 23). Stimulation of the sialyl 6-sulfo Lewis X-positive colon cancer cell line with a calcium ionophore ionomycin markedly reduced sialyl 6-sulfo Lewis X and induced cyclic sialyl 6-sulfo Lewis X expression. These results suggested that the metabolic conversion of sialyl 6-sulfo Lewis X into cyclic sialyl 6-sulfo Lewis X by a calcium-dependent enzyme, sialic acid cyclase, as we hypothesized for human leukocytes previously (C. Mitsuoka et al., Proc. Natl. Acad. Sci. USA, 96: 1597-1602, 1999), also occurs in nonmalignant colonic epithelia.

Colorectal Neoplasms↗
PubMed2000

Systematic identification of genes expressed during early oogenesis in medaka.

Subtractive hybridization was used to identify differences in gene expression between medaka (Oryzias latipes) males and females during sex differentiation. Fifty female-specific cDNA fragments were cloned. They can be classified into three groups by virtue of whether their earliest expression is at 1, 5, or 30 days after hatching. All 15 near full-length cDNAs belonging to the first two groups were cloned. Many of these female-specific genes are coordinately expressed in oocytes at the earliest stages of oogenesis. Some of the genes that were identified by their sequences include egg envelope proteins, oocyte-specific RNA binding proteins, and a transcription factor containing a basic helix-loop-helix motif.

Animals↗
PubMed2000

In-situ force in the medial and lateral structures of intact and ACL-deficient knees.

The anterior cruciate ligament (ACL) is the major contributor to limit excessive anterior tibial translation (ATT) when the knee is subjected to an anterior tibial load. However, the importance of the medial and lateral structures of the knee can also play a significant role in resisting anterior tibial loads, especially in the event of an ACL injury. Therefore, the objective of this study was to determine quantitatively the increase in the in-situ forces in the medial collateral ligament (MCL) and posterolateral structures (PLS) of the knee associated with ACL deficiency. Eight fresh-frozen cadaveric human knees were subjected to a 134-N anterior tibial load at full extension and at 15 degrees, 30 degrees, 60 degrees, and 90 degrees of knee flexion. The resulting 5 degrees of freedom kinematics were measured for the intact and the ACL-deficient knees. A robotic/universal force-moment sensor testing system was used for this purpose, as well as to determine the in-situ force in the MCL and PLS in the intact and ACL-deficient knees. For the intact knee, the in-situ forces in both the MCL and PLS were less than 20 N for all five flexion angles tested. But in the ACL-deficient knee, the in-situ forces in the MCL and PLS, respectively, were approximately two and five times as large as those in the intact knee (P < 0.05). The results of this study demonstrate that, although both the MCL and PLS play only a minor role in resisting anterior tibial loads in the intact knee, they become significant after ACL injury.

Adult↗
PubMed2000

The forces in the anterior cruciate ligament and knee kinematics during a simulated pivot shift test: A human cadaveric study using robotic technology.

PURPOSE: Although it is well known that the anterior cruciate ligament (ACL) is a primary restraint of the knee under anterior tibial load, the role of the ACL in resisting internal tibial torque and the pivot shift test is controversial. The objective of this study was to determine the effect of these 2 external loading conditions on the kinematics of the intact and ACL-deficient knee and the in situ force in the ACL. TYPE OF STUDY: This study was a biomechanical study that used cadaveric knees with the intact knee of the specimen serving as a control. MATERIALS AND METHODS: Twelve human cadaveric knees were tested using a robotic/universal force-moment sensor testing system. This system applied (1) a 10-Newton meter (Nm) internal tibial torque and (2) a combined 10-Nm valgus and 10-Nm internal tibial torque (simulated pivot shift test) to the intact and the ACL-deficient knee. RESULTS: In the ACL-deficient knee, the isolated internal tibial torque significantly increased coupled anterior tibial translation over that of the intact knee by 94%, 48%, and 19% at full extension, 15 degrees, and 30 degrees of flexion, respectively (P <.05). In the case of the simulated pivot shift test, there were similar increases in anterior tibial translation, i.e., 103%, 61%, and 32%, respectively (P <.05). Furthermore, the anterior tibial translation under the simulated pivot shift test was significantly greater than under an isolated internal tibial torque (P <.05). Under the simulated pivot shift test, the in situ forces in the ACL were 83 +/- 16 N at full extension and 93 +/- 23 N at 15 degrees of knee flexion. These forces were also significantly higher when compared with those for an isolated internal tibial torque (P <.05). CONCLUSION: Our data indicate that the ACL plays an important role in restraining coupled anterior tibial translation in response to the simulated pivot shift test as well as under an isolated internal tibial torque, especially when the knee is near extension. These findings are also consistent with the clinical observation of anterior tibial subluxation during the pivot shift test with the knee near extension.

Adult↗
PubMed2000

A detailed linkage map of medaka, Oryzias latipes: comparative genomics and genome evolution.

We mapped 633 markers (488 AFLPs, 28 RAPDs, 34 IRSs, 75 ESTs, 4 STSs, and 4 phenotypic markers) for the Medaka Oryzias latipes, a teleost fish of the order Beloniformes. Linkage was determined using a reference typing DNA panel from 39 cell lines derived from backcross progeny. This panel provided unlimited DNA for the accumulation of mapping data. The total map length of Medaka was 1354.5 cM and 24 linkage groups were detected, corresponding to the haploid chromosome number of the organism. Thirteen to 49 markers for each linkage group were obtained. Conserved synteny between Medaka and zebrafish was observed for 2 independent linkage groups. Unlike zebrafish, however, the Medaka linkage map showed obvious restriction of recombination on the linkage group containing the male-determining region (Y) locus compared to the autosomal chromosomes.

Animals↗
PubMed2000

cDNA cloning of putative rat acetyl-CoA transporter and its expression pattern in brain.

Rat acetyl-CoA transporter gene (Acatn) encodes a hydrophobic multi-transmembrane protein involved in the O-acetylation of gangliosides. O-acetylated gangliosides have been found to play important roles in the embryonic development of the nervous system. We have isolated rat Acatn cDNA by PCR cloning. The amino acid sequence of rat Acatn exhibited 92% and 96% homology with human and mouse sequences, respectively. The mRNA was expressed in brain at all developmental stages. Acatn expression was higher in embryonic and postnatal rats than in adult rats. Cellular localization of Acatn mRNA in adult rat brain was also analyzed by in situ hybridization. Acatn mRNA expression was detected in the neuronal cells of cerebellum, hippocampus, hypothalamus, cortex, olfactory bulb, and dorsal and ventral anterior olfactory nucleus in adult rat brain.

Amino Acid Sequence↗
PubMed1999

Cloning and characterization of a putative mouse acetyl-CoA transporter cDNA.

A mouse acetyl-CoA transporter (Acatn) cDNA was isolated by PCR cloning. Mouse Acatn exhibited 92% homology with human sequence on the basis of amino-acid sequence. The predicted gene product of Acatn is a 61 kDa hydrophobic protein with six to 10 transmembrane domains. Transfection of mouse Acatn cDNA into HeLa/GT3+ cells resulted in significant increase in the amount of 9-O-acetylated gangliosides, suggesting that Acatn does play an important role in the acetylation of gangliosides. Northern blot analysis of Acatn mRNA suggested that transcript of Acatn is widely distributed in various adult tissues. Expression of Acatn was found to be developmentally regulated, with high expression levels during early embryonic stages, and then there was a subsequent decrease in expression levels in the later embryonic stages.

Acetylation↗
PubMed1999

Reconstitution of functional L-selectin ligands on a cultured human endothelial cell line by cotransfection of alpha1-->3 fucosyltransferase VII and newly cloned GlcNAcbeta:6-sulfotransferase cDNA.

Recently, we proposed sialyl 6-sulfo Lewis X as a major carbohydrate-capping group of the L-selectin ligands on high endothelial venules in human lymph nodes. In this study we succeeded in reconstituting functional L-selectin ligands on a cultured human endothelial cell line, ECV304, by transfecting the alpha1-->3fucosyltranseferase VII (Fuc-T VII) and newly cloned GlcNAcbeta:6-sulfotransferase (6-Sul-T) cDNAs. The ECV304 cells transfected with Fuc-T VII cDNA expressed conventional sialyl Lewis X detected with specific antibodies including 2H5, whereas the cells transfected with 6-Sul-T cDNA expressed sialyl 6-sulfo lactosamine as well as MECA-79-defined carbohydrate determinants, but these singly transfected cells failed to express sialyl 6-sulfo Lewis X, as detected with the antisialyl 6-sulfo Lewis X mAb G152. Sialyl 6-sulfo Lewis X appeared only on the cells that were cotransfected with both 6-Sul-T and Fuc-T VII cDNAs. Significant adhesion of L-selectin-expressing cells was seen only to the doubly transfected ECV304 cells and was inhibited by G152. No adhesion was observed to the cells transfected either with 6-Sul-T or with Fuc-T VII cDNA alone. The mRNAs of the two enzymes were expressed or were inducible upon interleukin 1 stimulation in human endothelial cells. These results indicate that a set of carbohydrate determinants synthesized by the concerted action of the two enzymes, as typically represented by the sialyl 6-sulfo Lewis X-capping group, serves as an essential component of the ligand for L-selectin and that the reagents 2H5 and MECA-79, utilized in earlier studies to detect L-selectin ligand on high endothelial venules, recognize two different aspects of the same set of synthetic products.

Antibodies, Monoclonal↗